Corrugated bar.



PATENTED JULY 2, 1907.

A. L. JOHNSON.

R A B D B T A G U R R 0 G APPLIOATIOH IILBD NOV. 27. 1906.

BEST AVAILABLE. COPY r -"li' l, n it n fo i) ii ll. Lila lC- it. no in .lliilii PAilliillfiliif ALBERT LL ionuson, on LOUIS,

l lo. en ow.

Application filed November 27, 1965- Eerial No. 289,357.

Specification of Letters Faten't.

"oemnh non. r v. 1

concrete constructions and particularly to that class of bars whose crosseectionnl nrcais substantially uniform throughout their length. it has for its principal ob jects to produce a new form of corrugated bar having a uniform cross-section; to produce a. conngateel bar having projections or depressions arranged at such an angle to the axis of the bar that in any tranevcrse plane the area of the section through the projections or depressions will be equal to the area of such section in any other tranrwe'rse plane; to produce corrugated bar having projections or depressiomiinclined to the axis of the bar and so dispoo itively to each other as to ncutraiizo the forces tenomg to more the bar laterally; to overcome the objectionable results arising from ribs, projections 01' depressions inclined at an. angle to the axis of thebar; and other objects hereinafter more fully appearing.

Inthe accompanying drawings forming a pan. of this specifiuruion and wherein like symbols refer to like v parts wherever they occur, Figure l is a perspective View of the preferred form of bar; Fig. 2 in a view looking down upon the two faces made by the same roll; Fig. 3 is a view oionofacooi the preferred form of square bar; Fig. isaviowlmking at the odgcoi ihebarlormed at tho mcotingline of tho rol Fig. 5 is a cross-section through tho bar on the linov -3-5 of Figs=. 2 and 4, Fig. 6 is a cross 54 ,,l. ]ll through the boron tho lino f;----l3 of Figs. 2 and 4; Fig. 7 is a. plan View oi a flat baiflhaving indonlzuium in its opposite faces and ombodying tho invention; Fig. 8 is a longiturlimrl section on the line 8 8 of Fig. 7; and, Fig. .l is u II'AHM'IJI'SP section on the lino 9 of Fig. 7.

lu reinforced concrete construction it is desired to securo such :1 bond between the iron or steel bars and the concrete in which they are embedded that there shall be absolutely no relative movement. The tension bars are usually so located in the concrete that they extend in the direction of the tcusioual sire Therefore, the desired bond is secured by providing the bars with alternate ribs and lCIliQHSlUlIS transverse to the length of the bars. In the design of such bare the ribs were formerly permitted to fall at random on the several faces of the liillS uml, hence, there might be. transverse sections which would pass: through the doproreions or spec-w: between ribs on all tho Yucca-oi the llill. Other sections might puss through ribs on all the feces of the bar. But the bar could only bc strong as its weakest section. Therefore, the section in the plane pasing is, the net section of the bar, must be siuficiently la to give the bar the required strength. Obvious iaiger sectioun passing through one or n'iorc Iiool larger'aren than is requiredahd, i505!) the elm-midpoint a ooi'rugeted bar oi' uniform crosnscctum In which this woe-to is ohviateds The but there described has pains. of rows of alternate projections and spaces, the-projec;

tions being at right angles to the axis of thebar and, the

ro'ections and soacos of one row of each air of rows'is P 3 i i staggered with respect to the projections and epacesioi the other row oi the same pair of rows, whereby nny transverse plane will inteieect as many projections Qif ribs as spaces between the projections or ribs. Thue the cross-section of the bar is uniform and the mats] in the ribs or project no contributes tothe strength of the bar. By the bar herewith dinclosetl, the same uniformity of close-section is secured l) y the use of sloping or inclined ribs or projections 02' dopressions, their are rangement being such that the ribs of each face com pensate for the depressions, in the game face.

The preferred form of bar has four faces and. L ch iace in provided with a row of alternate ribs or projections l and depressions or spaces 2 between projections The ribs are parallel to each other and are inclined to the axis of the bar at su ch an angle that the centers of opposite ends of adjacent ribs are exactly oppos to each other, or in other words, similar poinui of opposite ends: of adjacent ribs lie in a line or piano at right angles to the axis of the bar. Thus, a right section at any point will contain equal areas of the rib: It may pz jqthrough only one rib of a face (an the ction 5--5 o 2) or it In 21:; through two rilr-s of :1. face (as the section 6: 6 of Fig. 2); but in either case theeree. oi the crolss section contributed by the rib or ribs:v is the some. If the depth of the spaces between ribs or proioctions be considered the same as the thickness of ribs, it may be said that in anyright section the areacontributod by the rib or ribs of any faccintersectcd is equal to the area of the space or spaces intersected. What is true oi one face is true of all the faces of the bar. Hence, the area of right sections of the bar uniiornr throughout the length of the bar. 1'

As stated above, the uniiorn'iity oi the eaeectional urea oi the bur is due to the fact that the shping ribs and spaces on each face are arranged to reciprocol componsute for each other at all points! This method ofcompeusation by inclining the ribs gives rise "hivei'ioui: stresses tending to move the bar laterally, to turn the bar on its axis, and to split the concrete. To guard against these stresses, the ribs and depressions of one face of the bar are arranged to inciine in. an oppoeite di rection to those of the next adjacent fiance but the angle,

through the depressions on all the faces of the bar, that 1 of inclination to the axial plane paeaingthrough the edge are equal Otherwise stated, every rib of one face of the bar is in the same plane with the rib opposite it on the next adjacent face, said plane being inclined equally to said surfaces and consequently being inclined to the axis of the bar. By this arrangement, the diagonal stresses on the ribs of one face due to a longitudinal stress tending to pocket the concrete in the angle between said ribs are balanced by the like stresses on the ribs of the adjacent face. As a longitudinal stress in the opposite direction would tend to split the concrete by a kind of wedge action, it is important to guard against it. For this purpose, the two remaining faces are considered as a pair, and their ribs arranged in parallel planes inclined to the axis of the bar as above described. The angle of inclination which the plane of the ribs of one pair of faces makes to the axis of the bar is equal to and opposite the angle made by the plane of the ribs of the other pair of faces; in fact, the two planes may coincide, if the diagonal half of the bar formed by one roll of the rolling mill shall have its ribs register with those of the other half of the bar which is formed by the second roll. In consequence of the ribs of one diagonal half of the bar being inclined in a direction opposite the direction of inclination of the plane of the ribs of the other diagonal half of the bar, the wedging action which would tend to split the concrete at one portion of the bar is offset by the pocketing action at the opposite portion.

It is advisable to leave a fillet 3 at the ends of the depressions in order to prevent the splitting of the concrete. In the practical manufacture of a rectangular bar the fillet is formed along the two diagonally opposite edges where the rolls meet; but the other two edges are preferably truncated on account of the difiiculty of keeping 'the rolls clean in practice. In the various 7 forms of flattened or elliptic bars (such as shown in Figs. 7, 8 and 9), however, the fillet is of greater importance.

What I claim as my invention and desire to secure by Letters Patent is:

the next adjacent depression.

2. A bar for reinforcing concrete having in each of two opposite faces a series of substantially equal transverselyinclined depressions arranged parallel with each other at a distance apart equal to the width of a depression, said depressions being inclined at such an'ungle that the initial point of the shoulder of one depression shali be in substantially the same transverse plane as the final point of the corresponding shoulder of the next adjacent depression.

3. A bar for reinforcing concrete having in each of two adjacent faces a series of substantially equal transverselyinclined "epressions arranged parallel with each other at a distarrbe'apart equal to the width of a depression, said depressions being inclined at such an angle that the initial point of the shoulder of one depression shall be in substantially the same transverse plane as the final point of the corresponding shoulder of the next adjacent depression, the respective ribs of said adjacent faces being in substantially the same planes.

4. A bar for'reinforcing concrete having a series of equal transversely-inclined depressions in each face arranged parnliel with each other at a distance apart equal to the width of a depression, the depressions of each face being separated by ribs and being inclined at such an angle that the sectional area of the depressions in any plane perpendicular to the axis of the bar shall be substantially equal to the sectional area of the ribs of said face in the SiilnL plane.

5. A bar for reinforcing concrete having on each fuce a series of equal transverselydnclined ribs arranged pnrnilcl with each other at a distance apart equal to the width of a rib, the ribs of each face being inclined at such an angle that the sectional area of the ribs in each face in any plane perpendicular to the axis of the bar shall be substantially equal to the sectional area of the spaces in said face in the same plane, and the respective ribs of the adjacent faces being opposite each other and in the same plane.

6. A bar for reinforcing concrete having on each face a series of equal transversely-inclincd ribs urrunged parallel with each other at a. distance apart cquzil to the width of the rib, the ribs of each face being inclined at such an angle that the sectional area of the ribs in each fucc in any plane perpendicular to the axis of the bur shall be substantially equal to the sectional area of the spaces in said face in the same plane. and the angle of inclination of the ribs of one face being equal to the angle of inclinntion of the ribs of the next adjacent face, but the ribs of said faces inclining in opposite directions.

7. A four-sided bur for reinforcing concrete having on each face a series of alternate ribs and spaces of equal width inclined to the axis of the bar, the angle of inclination being such that similar points in opposite ends of adjacent ribs of the same face shall be in a plane pcrpcir dicuiar to the nxisof the bar, each pair of ribs of two udjacent faces being in substantially the same plane with each other, and each pair of ribs 0!. the other two faces being also in substantially. the seine plane with each other, but the planes of said pairs of ribs being inclined to each other.

8. A four-sided bar for reinforcing concrete having on each face a series of alternate ribs and spaces ofv equal width inclined to the axis of the bar, the angle of inclination being such that similar points in opposite ends of ad jacent ribs of the same face shall be in a plane perpendicular to the axis of the bar, each pnirof ribs 01' two adjacent facesheing in substantially the same plane with each other, and each pair of ribs of the other two faces being also in substantially the same plane with each other, but the planes of said pairs of ribs being inclined to each other, and said bar having fillets along the edges where one pair of two adjacent faces meet the other two faces.

9. A four-sided bar for reinforcing concrete having on each face a series of alternate ribs and spaces of equal width inclined to the axis of the bar, the angle of inclina tlon being such that similar points in opposite ends of adjaccnt ribs of the same face shall be in a plane perpendicular to the axis of the bar, each pair of ribs of two adjacent faces being in substantially the same plune with each other, and each pair of ribs of the other two faces being also in substantially the same plane with each other, but the planes of said pairs of ribs being inclined to each other, and said bur having fillets along the edges where one pair of two adjacent faces meet the other two faces, the edges where the two adjacent faces of each pnlr meet being truncated.

ALBERT L. JOHNSON.

Witnesses:

Janus A. CARR, J. B. llineowzv. 

